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  <div class="section" id="numpy-ma-fromfunction">
<h1>numpy.ma.fromfunction<a class="headerlink" href="#numpy-ma-fromfunction" title="Permalink to this headline">¶</a></h1>
<dl class="data">
<dt id="numpy.ma.fromfunction">
<code class="sig-prename descclassname">numpy.ma.</code><code class="sig-name descname">fromfunction</code><span class="sig-paren">(</span><em class="sig-param">function</em>, <em class="sig-param">shape</em>, <em class="sig-param">**kwargs</em><span class="sig-paren">)</span><em class="property"> = &lt;numpy.ma.core._convert2ma object&gt;</em><a class="headerlink" href="#numpy.ma.fromfunction" title="Permalink to this definition">¶</a></dt>
<dd><p>Construct an array by executing a function over each coordinate.</p>
<p>The resulting array therefore has a value <code class="docutils literal notranslate"><span class="pre">fn(x,</span> <span class="pre">y,</span> <span class="pre">z)</span></code> at
coordinate <code class="docutils literal notranslate"><span class="pre">(x,</span> <span class="pre">y,</span> <span class="pre">z)</span></code>.</p>
<dl class="field-list simple">
<dt class="field-odd">Parameters</dt>
<dd class="field-odd"><dl class="simple">
<dt><strong>function</strong><span class="classifier">callable</span></dt><dd><p>The function is called with N parameters, where N is the rank of
<a class="reference internal" href="numpy.ma.shape.html#numpy.ma.shape" title="numpy.ma.shape"><code class="xref py py-obj docutils literal notranslate"><span class="pre">shape</span></code></a>.  Each parameter represents the coordinates of the array
varying along a specific axis.  For example, if <a class="reference internal" href="numpy.ma.shape.html#numpy.ma.shape" title="numpy.ma.shape"><code class="xref py py-obj docutils literal notranslate"><span class="pre">shape</span></code></a>
were <code class="docutils literal notranslate"><span class="pre">(2,</span> <span class="pre">2)</span></code>, then the parameters would be
<code class="docutils literal notranslate"><span class="pre">array([[0,</span> <span class="pre">0],</span> <span class="pre">[1,</span> <span class="pre">1]])</span></code> and <code class="docutils literal notranslate"><span class="pre">array([[0,</span> <span class="pre">1],</span> <span class="pre">[0,</span> <span class="pre">1]])</span></code></p>
</dd>
<dt><strong>shape</strong><span class="classifier">(N,) tuple of ints</span></dt><dd><p>Shape of the output array, which also determines the shape of
the coordinate arrays passed to <em class="xref py py-obj">function</em>.</p>
</dd>
<dt><strong>dtype</strong><span class="classifier">data-type, optional</span></dt><dd><p>Data-type of the coordinate arrays passed to <em class="xref py py-obj">function</em>.
By default, <em class="xref py py-obj">dtype</em> is float.</p>
</dd>
</dl>
</dd>
<dt class="field-even">Returns</dt>
<dd class="field-even"><dl class="simple">
<dt><strong>fromfunction</strong><span class="classifier">any</span></dt><dd><p>The result of the call to <em class="xref py py-obj">function</em> is passed back directly.
Therefore the shape of <a class="reference internal" href="#numpy.ma.fromfunction" title="numpy.ma.fromfunction"><code class="xref py py-obj docutils literal notranslate"><span class="pre">fromfunction</span></code></a> is completely determined by
<em class="xref py py-obj">function</em>.  If <em class="xref py py-obj">function</em> returns a scalar value, the shape of
<a class="reference internal" href="#numpy.ma.fromfunction" title="numpy.ma.fromfunction"><code class="xref py py-obj docutils literal notranslate"><span class="pre">fromfunction</span></code></a> would not match the <a class="reference internal" href="numpy.ma.shape.html#numpy.ma.shape" title="numpy.ma.shape"><code class="xref py py-obj docutils literal notranslate"><span class="pre">shape</span></code></a> parameter.</p>
</dd>
</dl>
</dd>
</dl>
<div class="admonition seealso">
<p class="admonition-title">See also</p>
<p><a class="reference internal" href="numpy.ma.indices.html#numpy.ma.indices" title="numpy.ma.indices"><code class="xref py py-obj docutils literal notranslate"><span class="pre">indices</span></code></a>, <code class="xref py py-obj docutils literal notranslate"><span class="pre">meshgrid</span></code></p>
</div>
<p class="rubric">Notes</p>
<p>Keywords other than <em class="xref py py-obj">dtype</em> are passed to <em class="xref py py-obj">function</em>.</p>
<p class="rubric">Examples</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">fromfunction</span><span class="p">(</span><span class="k">lambda</span> <span class="n">i</span><span class="p">,</span> <span class="n">j</span><span class="p">:</span> <span class="n">i</span> <span class="o">==</span> <span class="n">j</span><span class="p">,</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">3</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="nb">int</span><span class="p">)</span>
<span class="go">array([[ True, False, False],</span>
<span class="go">       [False,  True, False],</span>
<span class="go">       [False, False,  True]])</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">fromfunction</span><span class="p">(</span><span class="k">lambda</span> <span class="n">i</span><span class="p">,</span> <span class="n">j</span><span class="p">:</span> <span class="n">i</span> <span class="o">+</span> <span class="n">j</span><span class="p">,</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">3</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="nb">int</span><span class="p">)</span>
<span class="go">array([[0, 1, 2],</span>
<span class="go">       [1, 2, 3],</span>
<span class="go">       [2, 3, 4]])</span>
</pre></div>
</div>
</dd></dl>

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